Pot furnace



De@n 11,1928. 1,694,416

A. J. HANSON POT FURNACE Filed Nov. 9, 1927 Patented Dec. 11, 1,928.

UNITED STATESv PATENT OFFICE.

ALBERT" J. HANSON, OF ARLINGTON, MASSACHUSETTS, ASSIGNOR TO AMERICANMETALLURGICAL CORPORATION, OF BOSTON, MASSACHUSETTS, A CORPORATION OFMASSACHUSETTS.

POT FURNACE.

Applicatien led November, 11927. `Serial No. 232,036.

This invention relates tov pot furnaces more especiall. 'to these whichare electrically heated. Suc furnaces arecommonly used in the heattreatment of metal articles, the pot containing a molten bath such as ofcyanide into which the articles to be treated are immersed for a time.During the immersion and removal of the articles, the bath material isspa'ttered or drips more or less on the rim of the pot and thetop of thefurnace, from which it is liable to pass into the furnace outside of thepot and cause great damage to the re sistor heating units fwith which itmay come in I contact 1n view of its corrosive nature, par-Y ticularlywhen contacting with the highly heated resistors. f

In accordancewith the present'invention, therefore, the upper margin ofthe pot and cooperating parts at the top of the furnace are soconstructed as to be effectual in preventing access ofthe bath materialto the furnace interior. To thisend the pot is provided with anout-turned'marginal lip at its top presenting a plurality of flanges orridges withrwhich a complementally formed top member of the furnace engages. Preferably also the parts are so formed that thetop furnacemember eX tends over the marginal lip and engages the pot below itsupper edge so that any material` dripping on the furnace top is.directed into the pot below its top and is prevented from finding itsway into the furnace outside of the pot. As a further precaution thejointbetween the furnace top member and the pot may be sealedwith aresistant cement. sired also, the outer edge of the furnace top platemay be provided with one 0r more downwardly extending annular flangescooperating with similar upwardlyextending flanges of an outer top plateor portion of the furnace.

For a more complete'understanding of this invention, reference may behad to the accompanying drawings nwhich f vFigure 1 is a side elevationof a pot furnace constructed according to this invention.

Figure 2 is a fragmentary section on line 2-,-2l of Figure 1. p

As best illustrated lin Figure 2, the pot 1 is formed at its upper endwith an outwardly extendin marginal rim portion 2 provided with a purality of vertically upwardlypextending annular flanges 3 and 4, theflange 4 being at the extreme outer end of this portion If de-V yTheannularflange 5 of the pot margin may be seated outwardly of anupstanding inner marginal flange 12 of an annular plate 18. This plate13 may well be of a heat resistant alloy and is covered over by means ofan insulating layer 14 also ofannularform withinthe opening 15 `whichisshaped to conform to the "outer and lower edges of the portion 2 of thepot. This covering 14 may if desired be formed in plastic condition soas to make a close lit within the pot and with the plate 13 defines anannular groove within which the flange 5 of the pot engages. On theupper face of this portion 14 is shown an annular plate 16 which may beof a heat resistant alloy, or if the heat is not to be too great, ofcast iron. This plate 16 has a downwardly turned flange 17 which engagesover the flange 3 Vof the pot and contacts with the pot beneath itsupper edge. It may also have another annular downwardly directed flange18 which nests between the flanges 3 and 4 and is formed substantiallycomplementa] thereto. Any space between them may be filled with asuitable resistant cementitious material so as to seal the partstogether, thus preventing as far as possible the passage of bathmaterial therebetween by capillary or other action. This double sealwith the top plate 16 engaging over the margin of the pot and contactingwith the pot beneath its upper edge is quite effective for the purpose.

Particularly where the plate 16 is formed of alloy there may bepositioned outwardly thereof a second annular cover plate 20 formed ofcast iron or the like, this being cheaper than the alloy and beingeffective where the higher temperatures are not present. As shown thisplate 2O may have a pair flange portions 23 and on the outer edge of theannular plate l5. substantially complemental and may loe sealed togetherhy means of resistant cementitious where it might contact with 'theresistor elemente effectually prevented.

Hai' g thus described an embodiment of this; invention, it will heevident to those skilled in the art that varioua changes andmodifications might be made therein without departing from the spirit orScope of the invention.

I claim:

l. In combination, a furnacek having a potreceiving opening, a. pot inSaid opening having an upper marginal portion etendiiw` out-- wardly inposition to overlie a portion or said furnace, and an annular furnaceplate engaging lover said marginal portion and eX- tending below itsupper edge.

2. In combination, furnace having a potreceiving opening, a pot in .saidopening having an upper outwardly directed marginal portion arranged tooverlie a top portion of Theae parts are formedv ing, said rim having anupturned outer edge,

and an annular plate supportedon the top of Said'furnace and having adownturned inner Y margin, engr-.ging Said pot within said upturnededge.

In combination, a furnace having a potreceiving opening, a pot in saidopening having an outwardly directed marginal'liange,

an outer annular plate on the top yof Said furnace, an inner annularplate on the top of said furnace, the outer edge of said inner platebeing sealed tothe inner edge portion of' said outer plate, and saidmarginal flange being Sealed to the inner edge portion of saidinnerplate,.each of said `seals; comprising a plurality of interfittingflanges and channels and cementitious material therebetween.

In testimony whereof I haveaflixedl my signature.

ALBERT Jl Hanson.

